<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>array</title>
</head>
<body>

</body>
    <script>
        // var arr1=new Array()
        // var arr2 = new Array(10)
        // var arr3 = []
        // var arr4 = [1,2,3]
        // console.log(arr2.length)
        // arr2[0] = 5
        // arr2[3] = 3
        // console.log(arr2)
        // console.log(arr4[2])
        var arr7 = [1,"a"]
        arr7.push("q")
        console.log(arr7)

        arr7.pop()
        console.log(arr7)

        arr7.unshift("w")
        console.log(arr7)

        var m = arr7.shift()
        console.log(arr7)

        arr7.reverse()
        console.log(arr7)

        arr7.sort()
        console.log(arr7)
    </script>
</html>